Old lien... How to proceed?

[Rumen Mladenov]

Hi BP community!

I have a property under contract that has a lien from 1976 that has not been recorded as satisfied. House was sold in 1978 and then again in 1985, and I am purchasing it from the heir of the person who bought it in 1985. 

The seller can't find any of the documents from the 1985 purchase, and the lender on the 1976 loan is no longer in business - it was acquired by a different bank which was subsequently acquired by a third bank. Purchase is now on hold because of this, and it looks like my two options would be to walk away or take the risk and purchase it with this lien as exception on the title insurance. Has anyone faced this before? How did you proceed?